Profiled sheets have been described in South African patent number 93/9513. The South African Patent discloses, as illustrated in FIG. 6 of the present application, a profiled sheet (1) comprising two panel segments (2 and 3) which are laterally offset from each other, said panel segments being connected by virtue of a web formation (4) there-between. Furthermore there are included longitudinal groove formations (5 and 6) at the free end of each panel segment as well as longitudinal tongue formations (7 and 8) at the web formation (4).
The South African Patent discloses, as illustrated in FIG. 7 of the present application, when profiled sheets (1a, 1b and 1c) are assembled, the tongue formation (7) of sheet (1a) is snugly received in the groove formation (5) of sheet (1b), while the tongue formation (7) of sheet (1b) is similarly received in the groove formation (5) of sheet (1c).
At the upper surface of the structure the groove formation (6) of sheet (1a) snugly receives the tongue formation (8) of sheet (1b) and the groove formation (6) of sheet (1b) similarly receives the tongue formation (8) of sheet (1c).
In order to secure the sheets together, and over and above the fact that the tongue formations and groove formations inter connect in a snap fit fashion, it is necessary in practice to secure the sheets by placing rivets or roof bolts through the interconnected tongue and groove formations.
It will be appreciated that in order to carry this out it is necessary to rivet the tongue and groove formations on both sides of the assembled structure. This may often prove to be impractical and time consuming. A further disadvantage is that due to the rounded tongue and groove formations it is difficult to place close fitting borders around the sheets since the rounded formations in use cause the borders to be spaced from the panel segments.